Air-compressor



A. B. PE DERSEN.

AIR COMPRESSOR.

APPLICATION FILED JUNE 7. l9l9.

1,333,774. Patented Mar. 16,1920.

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@Z'gM I A TTUP/VE-YS A. B. PEDERSEN. AIR COMPRESSOR.

APPHCATION FILED JUNE 7| I919.

Patented Mar. 16,1920.

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Inventor Witnesse Q/ZCZW m 6 Woo nay;-

ALBERT ngrsnnnsmv, or EUREKA, urea.

aser-assesses.

To aZZ whom it may concern Be it known that I, ALBERT B. Pnnnnsnn,

a citizen of the'United States, and a 'resident of Eureka, in the county of Jua and State. of Utah, have invented certain new and useful.Improvements in Air-Comprea sers, of which the following is a speci: fication.

My invention is an improvement in air compressors, and has for its object to provide a device of the character specified esv pecially adapted for inflating the tires of motor vehicles, whereinthe compressor has a high and a low pressure side, the air comressed b the low ressure side oassin b freely through the high pressure side so that the high pressure side does not begin to coinpress until the'pressure in the tire attains a predetermined point.

In the drawings:

Figure 1 is a front view of a pump constructed in accordance with the invention, with parts broken away;

Fig. 2 is a front View of the piston, with parts in section;

Fig. 3 is a side view.

I In the embodiment of the invention shown the cylinder of the pump consists of two portions 1 and 2 of unequal diameter, the portion 2 havinga suitable head 3 at the end. remote from the portion 1 which acts as a' base and is provided with a central port into which is threaded a nipple 4-. This nipple has its inner end beveled to form a valve seat, and a conical valve 5 cooperates with the seat, the valve being nor mally held to its seat by a coil spring which is arranged within a recess in the stem of the valve between the valve and a pin 7 extending transversely of the nipple.

the portion 1 and this piston is rigid with a piston'l l; fitting within the portion. 2 and reciprocating therein. The combined pistons are reciprocated by means ofa shaft 15 which is journaled in a bearing arm 16 on the portion 2, and the bearing arm has a disk 17 which is provided with an eccentrio crank 18. The crank pinlS has a roller *Applioaition filed June 7, 119 12: Serial No. 302,376.

end has avalve. I threaded a valve seat. 21,.and a ball valve Specification'of Letters iatent. Fatantadl B131; 192i or bushing 19 which moves in a transversely arranged guideway 20 rigid with the combined piston, the arrangement being such that when the shaft 15 is rotated the pistons will be simultaneously reciprocated, one I drawing air into its'cylinder while the other.

forces the air out. It will be noticed that the upper end of the portion 1 of the cylin der has annular ribs or fins 21 for assistin 3 piston rings.

. in cooling, and both pistons have the usual I Referring to Fig. 2 .it will be seen, that" the double piston isshollow, and that each In the piston a there is 22 cooperates with the seat, a spring '23 normally holdingthe valve closed, the said spring being arranged between the valve and the cross p1n'2 l 1n the seat.

A valve seat 25 is threaded intothe upper end of the double piston, that is, into the portion 13, and with this seat cooperates a conical valve 26. The stem of the valve is hollow and a coil'spring 27 is arranged therein, between the valve and a cross pin 28 in the seat. It will be noticed that the seat has a marginal flange 29 at its upper end, which fitsupon theend of the piston and a gasket 30 is arranged between the.

flange and the piston.

In operation, when the double piston moves upwardly, air is drawnpast the valve 5. while at the same time the air above the piston 13'is driven out pastthe valve 11. hen the doublepiston moves downward, the airbelow the piston 14lis compressed,

since it cannot pass out by way of the valve equals that in the portion 2 of the pump,

the portion 1 of the pump will come into operation to compress the air to a higher degree and to complete the lnflatlon of the 'pump. So long as thispressure in the t1re is not equal to that in the cylinder 2, there i will be no compression in the cylinder 1.

:I claim: 1

a An air compressor comprising axially ahn 'd cylinders of different characters con- :gtituting liigli and low pressure cylinders, a-single pistonxdisposed within said eylfinders andhaving one end of a diaineter to fit Within the smaller cylinder and'liaying its other end enlarged to Ifit Withintlie larger cylinder, said piston being 'fo r'nied 1 ,easym seats, an inwardly opening check valve closing theseat atthe enlarged end of the piston, an outwardly opening check valve closing the'seat at'the smaller end of the piston; and means for reciprocating the M piston. hollow and having the ends of its bore 'closed by members provided with 'valveff .IALBERTVBQPEDERSQEN. 

